Affordable Access

deepdyve-link
Publisher Website

Dynamic nuclear polarization of sedimented solutes.

Authors
  • Ravera, Enrico
  • Corzilius, Björn
  • Michaelis, Vladimir K
  • Rosa, Camilla
  • Griffin, Robert G
  • Luchinat, Claudio
  • Bertini, Ivano
Type
Published Article
Journal
Journal of the American Chemical Society
Publisher
American Chemical Society
Publication Date
Feb 06, 2013
Volume
135
Issue
5
Pages
1641–1644
Identifiers
DOI: 10.1021/ja312553b
PMID: 23331059
Source
Medline
License
Unknown

Abstract

Using the 480 kDa iron-storage protein complex, apoferritin (ApoF), as an example, we demonstrate that sizable dynamic nuclear polarization (DNP) enhancements can be obtained on sedimented protein samples. In sedimented solute DNP (SedDNP), the biradical polarizing agent is co-sedimented with the protein, but in the absence of a glass-forming agent. We observe DNP enhancement factors ε > 40 at a magnetic field of 5 T and temperatures below 90 K, indicating that the protein sediment state is "glassy" and suitable to disperse the biradical polarizing agent upon freezing. In contrast, frozen aqueous solutions of ApoF yield ε ≈ 2. Results of SedDNP are compared to those obtained from samples prepared using the traditional glass-forming agent glycerol. Collectively, these and results from previous investigations suggest that the sedimented state can be functionally described as a "microcrystalline glass" and in addition provide a new approach for preparation of samples for DNP experiments.

Report this publication

Statistics

Seen <100 times